The reserves of light rare earth elements are abundant and the price is relatively cheap. The development of light rare earth metals for the manufacture of sintered NdFeB materials is worth encouraging.
La, Fe, and B metals are difficult to form La2Fe14B, and the temperature is very narrow, but once formed, it is stable below 860°C. Nd accounts for 65%-75% of the cost of sintered NdFeB. At this stage, the cost of La is about one-tenth of Nd. Substituting La for Nd can reduce costs and promote the comprehensive utilization of rare earth resources. With the increase of La content, the magnetic polarization intensity Js, remanence Br, coercive force Hcj and maximum magnetic energy product (BH) m of the alloy will all decrease. La is a non-magnetic atom. Due to the effect of magnetic dilution, (BH)m decreases Much faster than Br decreases.
The stability of Ce2Fe14B is poor and it is more difficult to form. With the increase of Ce content, various magnetic properties are reduced. At the same time, the addition of Ce will cause the Curie temperature and temperature stability of the magnet to decrease.
The Pr2Fe14B compound has several basic conditions that can be used as a permanent magnetic material. It can be sintered at about 1060°C to obtain better magnetic properties. Using (PrNd)-Fe metal as a raw material can produce sintered NdFeB permanent magnets with good magnetic properties. It should be noted that Pr is easier to oxidize than Nd, and the amount of Pr must be appropriately controlled for some materials that require high stability.